<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    #box {
      width: 300px;
      height: 300px;
      margin: 50px auto;
      background-color: rgb(117, 91, 61);
    }
    #box2 {
      width: 300px;
      height: 300px;
      margin: 20px auto;
      background-color: rgb(97, 117, 61);
    }
    #box3 {
      width: 300px;
      height: 300px;
      margin: 20px auto;
      background-color: rgb(231, 112, 33);
    }
  </style>
</head>

<body>
  <div id="app">
    <button @click="showHide">
      {{ num }}
    </button>
    <div v-if="num%3===0" id="box">111</div>
    <div v-else-if="num%3==1" id="box3">222</div>
    <div v-else id="box2">333</div>
  </div>
  <script src="./vue.js"></script>
  <script>
    const vm = new Vue({
      el: '#app',
      data: {
        num: 0
      },
      methods: {
        showHide(){
          this.num++;
        }
      }
    })
  </script>
</body>

</html>